1. Field of the Invention
The present invention relates to a canister mounting structure which mounts a canister for adsorbing fuel vapor, on a vehicle body.
2. Description of the Related Art
A canister for adsorbing fuel vapor generated within an automotive fuel tank is known in JP-A-5-187330 and JP-A-9-21361 in which an interior of the canister is divided into a main chamber and a sub-chamber, so that the main chamber connects to the fuel tank and an intake passageway of an engine, while the sub-chamber communicates with the atmosphere, whereby fuel vapor is designed not to be blown out to the atmosphere.
Additionally, a canister for adsorbing fuel vapor generated within an automotive fuel tank is known in JP-A-7-12012 and JP-A-9-25855 in which, in order to mount the canister on a vehicle body, mounting brackets provided on the outer circumference of the canister are mounted on the vehicle body with bolts.
FIG. 7 shows one example of a conventional canister C mounting structure in which the canister is mounted on a vehicle body with bolts via mounting brackets provided on the outer circumference of a casing of the canister. That is, three mounting brackets 01a . . . are provided on the outer circumference of the casing 01 of the canister C in such a manner as to protrude outwardly. There are then provided three bolts 03 . . . which pass through the mounting brackets 01a . . . and a mounting plate 02 from the bottom to the top. Nuts 04 . . . are then fastened to the bolts 03 . . . so as to fix the casing 01 to the mounting plate 02. Thereafter, nuts 06 . . . are fastened to four bolts 05 . . . which pass through the mounting plate 02 and the vehicle body 07 from the bottom to the top, so as to fix the mounting plate 02 to the vehicle body 07.
With the canisters disclosed in JP-A-7-12012, JP-A-9-25855 and FIG. 7, since the mounting brackets of the canister are provided on the outer circumference of the casing thereof, there is caused a problem that the canisters are enlarged by such an extend that the mounting brackets protrude outwardly.
The invention was made in view of this situation, and an object thereof is to mount a canister comprising a main chamber and a sub-chamber on the vehicle body in a compact fashion.
With a view to attaining the object, according to a first aspect of the invention, there is provided a canister mounting structure for mounting a canister on a vehicle body with bolts, the canister comprising a casing having formed therein a main chamber and a sub-chamber each housing therein a fuel absorbent, a communicating path for providing a communication between the main chamber and the sub-chamber, a charge port for connecting the main chamber to a fuel tank, a purge port for connecting the main chamber to an intake passageway of an engine and an atmosphere communicating port for allowing the sub-chamber to communicate with the atmosphere, wherein the bolts are disposed in mounting portions formed between the main chamber and the sub-chamber of the casing.
According to the structure above, since the bolts for mounting the casing of the canister on the vehicle body are disposed at the mounting portions formed between the main chamber and the sub-chamber of the casing, it becomes possible to obviate a necessity of providing the mounting brackets on the outer circumference of the casing, whereby the casing can be miniaturized, thereby making it possible to mount the canister on the vehicle body in a compact fashion. Moreover, since the bolts do not have to be put through the main chamber and the sub-chamber, it becomes possible to obviate a necessity to seal bolt holes.